Active Idd consumption test in 4Meg DRAM failure analysis

Active current consumption testing measures the current of the device while in active operation. During device operation, the device transistors switch from one state to another as the input signal propagates through the device. Eventually, the signal would have completed triggering the transistors and reach steady state condition. In this paper, the analysis was done on 4meg dram using 0.6 micron CMOS technology. Idd consumption testing has been more successful in CMOS devices due to its complementary arrangement of transistors. At steady state, one of the transistors will be “shorted” to either Vdd or Vss, while the other complementary transistor is “open”. Any defect that exists resulting in a bridging or open fault at the transistors would give an abnormal steady state current. In bridging fault, the current increase can be milliamps from the nanoamps of steady state current. Open faults normally leads to a stuck-at fault. In the case of open, it is dependant on how the defective transistors affect the next stage of transistors or circuits